1. Field of the Invention
The invention relates to a photographic film supply and threading assembly for use in a high speed camera.
2. Description of the Prior Art
In the past it has been common practice to use open reels of film in high speed microfilm cameras used to photograph financial documents. In order to install the film in the camera, a supply reel would be mounted on a suitable spindle. A portion of the film would then be unwound from the supply reel and be carefully fed through a system of film advance rollers and idler rolls and over a capstan followed by more rollers before being attached to a suitable take-up reel. This was a very time-consuming and intricate task since it had to be done within the confines of the camera body. Great care had to be exercised in positioning the film so that it would feed properly at high speed and not jam or come off any of the pulleys or rollers in the feed path. Also, care had to be taken to not move or damage any portion of the lens system of the camera.
The film transport assembly of the present invention allows the supply reel of film to be put in place and the film to be fed around spaced guide rollers to the take-up reel while the assembly is outside of the camera body. After loading, the film transport assembly can be put into position in the camera where the film is brought to the image plane and automatically tensioned and prepared for movement in the camera without the film having to be handled again by the operator.
The field in which the present invention is expected to be employed, that of high speed microfilming of documents as in a check processing environment, will benefit by enhanced speed of film movement and greater simplicity of film loading and unloading. In this area, representative of prior art relating to film transport motor controls, in the applicant's opinion is the U.S. Pat. No. 4,058,266, granted Nov. 15, 1977 to Jack Beery. Jack Beery is also the inventor of U.S. Pat. No. 4,087,173 granted May 2, 1978, relating to a document photography system which has been incorporated in earlier devices sold by Unisys Corporation and its predecessors. Other patents of interest might include U.S. Pat. No. 4,175,719 granted Nov. 27, 1979 to Speckman (illustrating a cartridge which may be used in connection with the present invention); U.S. Pat. No. 3,209,644 granted Oct. 5, 1965 to Simmon et al relating to reeling and unreeling of a different device; and U.S. Pat. No. 3,478,985 granted Nov. 18, 1969 to Richard Tobey relating to a still different tape transport. A less desirable device is illustrated by U.S. Pat. No. 4,037,239 of July 19, 1977 to Jamieson et al. The invention of this application represents a novel and significant improvement in light of such prior devices.